The current study investigated the physicochemical and structural properties of different ratios of psyllium gum (PG) and modified starch (MS) (100:0, 50:50, 75:25, 0:100) composite films. The results indicated that the moisture content, water solubility, water vapor permeability (WVP), and tensile strength (TS) of films decreased with increasing proportions of PG. However, the films’ elongation at break (EB) increased with gum content >50%. Cross‐sectional scanning electron microscopy (SEM) of composite films showed homogeneity, integrity, and a smooth structure. The results of differential scanning calorimetry (DSC) indicated a reduction of thermal stability with increasing proportions of PG. The films’ Fourier transform infrared spectroscopy (FTIR) spectra indicated miscibility and good interactions between MS and PG. These findings were in agreement with the results of physicochemical, mechanical, morphological, and thermal analyses. The PG/MS composite films with improved properties have potential for use in food packaging. Practical applications The film forming is a technique that polymer(s) combine with together and may be created cross‐linked between them. The combination of polymers for film forming was used for reinforcement and stability the films networks. In this study, the composite edible films of psyllium gum/modified starch made and the physicochemical, mechanical, and structural properties of films was measured.

Background: Plantago ovata Forsk (Psyllium seed) is an annual plant of plantago genus. This plant widely grows in India and Iran. The Psyllium seed contains mucilage, protein, sugar, fat and tannins. Seed’s husk is a known source to extract hydrocolloid. Objective: The aim of this study was to optimize gum extraction from the Psyllium seed. Methods: The response surface methodology (RSM) was used to estimate the effect of independent variables on the extraction yield of Psyllium gum. The obtained experimental data were fitted to a second- order polynomial equation using multiple regression analysis and analyzed by appropriate statistical methods. A central composite design (CCD) was used for experimental design and analysis of the results to obtain the best possible combination of extraction temperature (X1= 60-80°C), extraction time (X2= 1-3 h), and the ratio of water to raw material (X3= 30-70%) for the maximum gum extraction. Results: Optimum extraction conditions were extraction temperature of 79°C, extraction time of 2.5 h, and the ratio of water to the raw material of 57%. The experimental extraction yield under optimal conditions was found to be 9 ± 0.25%, which was in agreement with the predicted value of 9.4%. Conclusion: This study showed that Psyllium gum can be used as a hydrocolloid source for pharmaceutical and food industry such as edible films for food packaging.